TerraSAR-X capabilities and constrains for acquisitions over the polar regions. Dana Floricioiu

Transcription

1 TerraSAR-X capabilities and constrains for acquisitions over the polar regions Dana Floricioiu STG IPY SAR Workshop Montreal 5/6 March 2008

2 TerraSAR-X Features Multi-Mode Imaging StripMap (High-Resolution) SpotLight ScanSAR Multi-Polarization single dual ( & twin) 100, 150, 300 MHz Bandwidth Up to 1 m resolution for High-Resolution SpotLight Multi-Geometry 20º - 45º ( 55º Spotlight) full perf. incidence angle range extended range: 15º - 60 º left-looking (high priority orders only) Dual-Receive Antenna Configuration redundant receiver chain fore and aft antenna quad polarization Folie 2

3 TerraSAR-X Basic Imaging Modes Stripmap (SM) Θ 1 =20 o High Resolution Spotlight (HS) & Spotlight (SL) ScanSAR (SC) >30 km Θ 2 =45 o 10 km 5-10 km 100 km Stripmap Spotlight (HS & SL) ScanSAR swath width (range) 30 km (single pol.) 15 km (dual pol.) MHz chirp BW azimuth: 5 / 10 km (HS / SL) 100 km (only single pol.) full performance incidence angle range azimuth resolution 3.3 m (single pol.) 6.6 m (dual pol.) 1.1 m / 2.2 m (HS, single / dual pol.) 1.7 m / 3.4 m (SL, single / dual pol.) 17 m (1 look, 4 beams) ground range 150 MHz chirp BW 1.7 m m (@ ) 1.5 m m (@ ) 1.7 m m (@ ) (nom.) product length 50 km 5 km/10 km 150 km polarizations: single HH or VV dual (HH/VV) (HH/HV) or (VV/VH), no cross-pol for SL,HS

4 TerraSAR-X full performance beams and incidence angle ranges* Imaging Mode Polarization Mode Full Performance Beam Configurations Incidence Angle (Look Angle) Range Stripmap single strip_003- strip_ ( ) Stripmap dual stripnear_003 - stripfar_ ( ) Spotlight & High-Resolution Spotlight single & dual spot_010 spot_ ( ) ScanSAR single scan_003 scan_ ( ) *for right looking mode These are the only beams which can be ordered in EOWEB Folie 4

5 TerraSAR-X Product Tree Different applications require a variety of basic product types Several product variants are generated from each of the possible imaging / polarisation mode combinations TS-X Datatake L0 Products L0 L1b Products SSC MGD RE SE GEC EEC RE SE RE SE Value added products RE- radiometric enhanced SE- spatially enhanced Folie 5

6 Detected Product Variants: projections MGD: multi look ground range detected homogenous ground spacing no interpolation artifacts due to image rotation. geo-referenced GEC: geocoded ellipsoid corrected UTM / UPS projection, WGS84 reference, average height from DEM EEC: enhanced ellipsoid corrected UTM / UPS projection, WGS84 reference, coarse DEM considered (e.g. SRTM, DTED-1 and -2) pixel localization accuracy down to meter level depends on DEM availability/quality North East Upsala glacier, Patagonia

7 Spatially Enhanced Products (SE) designed for the highest possible square ground resolution. Radiometrically Enhanced Products (RE) optimized with respect to radiometry range and azimuth resolution are intentionally decreased -> reduce speckle (~ 6 looks) -> radiometric resolution ~ 1.5 db. reduced product data size. More about TerraSAR-X products: TX-GS-DD-3302_Basic-Product-Specification-Document_1.5.pdf (recent released) TX-GS-DD-3307_Level-1b-Product-Format-Specification_1.3.pdf Folie 7

8 Orbit Type Accuracies (1) two GPS receivers on-board TerraSAR-X: 2- frequency IGOR (GFZ provision) nominally used 1-frequency MosaicGNSS backup Quicklook nominal input: IGOR GPS navigation solutions (Mosaic as backup) accuracy requirement: 10 m (covering Mosaic) Predicted based on Quicklook orbit determination propagated for next 24 hours accuracy requirement: 700 m along track Rapid nominal input: IGOR GPS raw data (Mosaic as backup) accuracy requirement: 2 m; currently achieved: 20 cm auxiliary data: JPL real-time GPS products (RTG) Science input: IGOR GPS raw data -> Accurate corregistration accuracy requirement: 0.2 m to subpixel level target accuracy: 0.1 m auxiliary data from University of Bern (CODE): more accurate than RTG, but latency (currently < 10 days) Folie 8

9 Orbit Type Accuracies (2) Science Orbit Accuracy Assessment Orbit assessment using Satellite Laser Ranging (SLR) measurements Daily RMS (root mean square) indicates an agreement of 2.4 cm (on the average) with the SLR range measurement (all stations, 10 deg elevation limit) 3D absolute orbit accuracy can be said to be better than 10 cm in the RMS sense (requirement: 20 cm) Folie 9

10 Orbit Type Accuracies (3) The TerraSAR-X products are processed with the best available orbit type at the time of processing but at least with the ordered/required one. This means that catalogue orders: usually science orbit available future orders: selecting science orbit at ordering usually does not delay delivery by more than 10 days Folie 10

11 TerraSAR-X processor: DEM Database Specifications consistent usage of digital elevation model throughout processing chain 10 arcsec (approx. 300 m) reference DEM for processing o merged from 3 arcsec SRTM C-Band and Globe 2.0 o accuracy class: SRTM C: 8m / 16 m rel/abs GLOBE : varying m for geocoding 1 or 3 arcsec, best locally available (for polar regions: GLOBE only) geolocation information velocity parameter radiometric corrections (projected antenna pattern) geometric Doppler determination based on attitude info, DEM, beam-pointing info and orbit info Folie 11

12 X-band for snow and ice applications (1) Microwave penetration depth in snow ρ = 0.4 gcm -3 d p = λ0 2π ε ε" X-band C-band Dry: Vw=0%vol d p = 30 m 55 m Wet Vw=1%vol: d p = 0.06 m m Wet Vw=2%vol: d p = 0.03 m 0.07 m Penetration depth [ m] V w [%] Folie 12

13 X-band for snow and ice applications (2): modeled components and total backscattering X-band VV for dry snow Snow depth: 1 m; V w =0% vol Air/snow: σ h = 4 mm, L=110 mm Snow/ground: σ h = 15 mm, L=80 mm Ground: ε r =15-i 4.7 Snow: ε r =1.53-i Folie 13

14 X-band for snow and ice applications (3): Seasonal change of backscattering of snow at L-, C- and X-band? X-band HV of dry snow? Folie 14

15 11 ScanSAR 114 Stripmap 58 HS 23 SL TSX Acquisitions mid November Feb (commissioning phase not included) Folie 15

16 Arctic: 10 ScanSAR 252 Stripmap 138 HS,106 SL Folie 16 TSX Acquisitions mid November Feb. 2008

17 TerraSAR-X maximum coverage (nadir) towards the North pole 82.6 N Northermost TSX acquisitions Spotlight mode ~55deg incidence angle, 88.1 N Folie 17

18 TerraSAR-X maximum coverage (nadir) towards the South pole 82.6 S With left looking and incidence angle about 58 deg (not Full performance) up to 89 S possible Folie 18

19 Examples of TerraSAR-X image products Folie 19

20 Stripmap - Left looking Beardmore glacier (complex flow fields) 85.0 S W Incidence angle: 41 deg Strip_012 L/Asc Polarization: HH Left looking: impact on mission operations (solar antenna, SAR antenna orientations) products have degraded performance Flight dir (Asc) DT 5944 Range dir. ~30 Folie km20

21 Stripmap, dual polarization East Greenland, glaciers, Polarisation: HH/HV Incidence Angle: deg (beam: stripnear_005 R) 68.3N 31.1W HH,HV,HH-HV HV HH Range dir. Flight direction (Desc) 15 km Folie 21

22 Stripmap, dual polarization W Greenland, Polarisation: HH/VV Incidence Angle: deg (beam: stripfar_008 R) 78.9 N, 66.5 W HH,VV,HH-VV VV HH Range dir. Flight direction (Desc) ~15 Folie km 22

23 Stripmap, dual polarization Sea Ice 74.0S 51.9W, Polarization: HH/HV Incidence Angle: 15 deg (beam: stripnear_001 R), Desc HH,HV,HH-HV DT 5274 Folie 23

24 Stripmap Ice breaker Shirase on the way to Syowa HH Incidence angle: 29 deg Strip_006 Asc. DT398 Folie 24

25 High Resolution Spotlight 300 MHz Sanae IV Station Polarization: HH Incidence angle: deg (beam:spot_063 R) ~10 km Scene size : 10km rg x 5km az Flight dir (Asc) Range dir. Folie 25

26 High resolution spotlight, 300 MHz Maitri station (70.7 S, 11.8 E) Polarization:HH ~10 km Incidence angle: deg (beam:spot_060 R) Scene size : 10km rg x 5km az Flight dir (Asc) Range dir. Folie 26

27 High resolution spotlight: Troll station; ; 72.0 S, 2.3 E; Polarization: HH; Incidence angle: 28 deg (beam: spot_025r) ~10 km DT 5274 Folie 27

28 ScanSAR NW Greenland 80.8 N, 66.2 W, Agassiz Ice Cap/ Petermann Glacier Polarization: VV Incidence angle: deg (beam:scan_007 R) Scene size : 100 km rg x 150 km az Range dir. Flight direction (Desc) Folie 28

29 Stripmap GEC SE NW Greenland 80.8 N, 66.2 W Polarization: VV Incidence Angle: deg (beam:strip_008r) Flight dir (Asc) Datatake:NSG 2629 Range dir. Folie 29

30 ScanSAR Filchner Ice shelf 77.7 S, 38.9 W Polarization: HH Incidence angle: deg (beam:scan_014r) Range dir. Flight direction (Desc) 100 km Berkner I. Filchner Ice shelf Folie 30 Datatake: NSG 9500

31 ScanSAR, Neumayer station Polarization: HH Incidence angle: deg (beam:scan_006r) Range dir. Flight direction (Desc) Datatake: NSG 9501 Datatake:NSG 9501 Folie 31

32 Pine Island break off Oct Datatakes: NSG 7525, 7543, 7560, 7571, 7586, ScanSAR Folie 32

33 Access to TerraSAR-X data for scientific use in IPY Pre-launch accepted proposals: COA0195 Ronald Saper (Vantage Point International) active HYD0270 Alexander Braun (University of Calgary) active LAN0066 Kenneth Jezek (Ohio State University) not active - activation ongoing LAN0013 Mathias Braun (University of Bonn) active MTH0123 Wolfgang Rack (AWI) activation ongoing MTH0176 Kjell Arild Hogda (Norut IT) activation ongoing OCE0116 Detlev Stammer (University of Hamburg) activation ongoing Submission of new proposals (open any time) See presentation on accessing TSX data for scientific use Folie 33